Diabetes mellitus is a lifestyle disorder that is rapidly becoming a major threat to populations all over the globe. Over the past 30 years, the status of diabetes has changed from being considered as a mild lifestyle disorder of the elderly to one of the major causes of morbidity and mortality, affecting people of all ages. There seems to be a renewed interest in herbal medicines across the world today and plants are a powerhouse of sources for antidiabetic drugs. The number of higher plant species on this planet estimates at 250,000. Of these, only about 6% have been screened for biologic activity and a reported 15% have been evaluated phytochemically. According to the WHO, 21,000 plants are used medicinally around the world by 65% of the world’s population. The need for writing this review of antidiabetic medicinal plants came from the need to relate information about various medicinal plants with antidiabetic activity, in order to restore the ethnomedical knowledge of antidiabetic plants. This book will be of immense use to the scientific community to easily access the research data on antidiabetic plants for their therapeutic application.